Hall of Infinite Doors

You wander towards your van in a hurry. You don't know how much longer the parents are going to take to pick up their child. You rush over and grab the two-square ball and look back at the child. He seems as though he has been occupying himself by drawing on the two-square cement with a piece of discarded chalk. You'd better get the kid into the car quickly, or you might have wasted the entire evening! You walk back over to your target. He's drawing guns and stick-figure battles in pink chalk.